[Federal Register Volume 62, Number 196 (Thursday, October 9, 1997)] [Rules and Regulations] [Pages 52655-52659] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 97-26792] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 97-SW-15-AD; Amendment 39-10153; AD 97-20-16] RIN 2120-AA64 Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) (Eurocopter) Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1 Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule; request for comments. ----------------------------------------------------------------------- SUMMARY: This amendment supersedes an existing airworthiness directive (AD), applicable to Eurocopter Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters, that currently requires initial and repetitive inspections of both surfaces of the tail boom vertical fin (vertical fin) spar, the skin, and the left-hand and right-hand frame sheets for cracks or loose rivets. This amendment requires the same initial and repetitive inspections of the vertical fin spar that are required by the existing AD, and also requires repairing certain cracks, if found, and repairing and reporting loose rivets and certain other cracks, if found. This amendment is prompted by an accident which occurred on April 15, 1997, resulting in one fatality. A subsequent investigation revealed that the vertical fin had failed as a result of a fatigue crack that initiated on the left side of the vertical fin spar cap. The actions specified by this AD are intended to prevent failure of the vertical fin and subsequent loss of control of the helicopter. DATES: Effective October 24, 1997. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 24, 1997. Comments for inclusion in the Rules Docket must be received on or before December 8, 1997. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of Regional Counsel, Southwest Region, Attention: Rules Docket No. 97-SW-15-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. The service information referenced in this AD may be obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This information may be examined at the FAA, Office of Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. FOR FURTHER INFORMATION CONTACT: Mr. Richard Monschke, Aerospace Engineer, Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5116, fax (817) 222-5961. SUPPLEMENTARY INFORMATION: On April 25, 1997, the FAA issued priority letter AD 97-09-16, to require inspecting both surfaces of the vertical fin spar, part number (P/N) 105-304061.03, P/N 1120-30406.03, or P/N 117-30423-03, paying particular attention to the area extending from the top edge of the second lightening hole from the top of the vertical fin spar to the bottom edge of the fourth lightening hole, the outer skin (skin), and the left-hand and right-hand frame plates for cracks, loose rivets, or other anomalies. This inspection must be performed before further flight, then repeated at intervals not to exceed 100 hours time-in-service. That action was prompted by an accident involving a Eurocopter Model MBB-BK117 series helicopter, which occurred on April 15, 1997, resulting in one fatality. A subsequent investigation revealed that the vertical fin had failed as a result of a fatigue crack that initiated on the left side of the vertical fin spar cap. The crack propagated across the spar cap and spar web until only the skin was carrying the flight load. The skin then started cracking, with the crack propagating horizontally toward the vertical fin leading edge until catastrophic overstress occurred. Inspections of other helicopters of the same type design revealed cracks in the vertical fin spars of three additional helicopters. That condition, if not corrected, could result in failure of the vertical fin and subsequent loss of control of the helicopter. Since the issuance of that AD, the manufacturer has developed repair procedures for the cracks, which were unavailable at the time of the release of the priority letter AD, and has issued Eurocopter Alert Service Bulletin MBB-BK117 No. ASB-MBB-BK117-30-106, Revision 3, dated May 5, 1997, which specifies repair procedures for the spar cap, as well as subsequent inspection requirements. This helicopter model is manufactured in The Federal Republic of Germany and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral [[Page 52656]] airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the Luftahrt-Bundesamt (LBA) has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. Since an unsafe condition has been identified that is likely to exist or develop on other Eurocopter Model MBB-BK117 series helicopters of the same type design, this AD supersedes AD 97-09-16 to require inspecting both surfaces of the vertical fin spar, part number (P/N) 105-304061.03, P/N 1120-30406.03, or P/N 117-30423-03, paying particular attention to the area extending from the top edge of the third lightening hole from the top of the vertical fin spar to halfway between the fourth and fifth lightening hole (see Figure 1 for description of area to be inspected), the skin, and the left-hand and right-hand frame sheets for cracks or loose rivets. This inspection must be repeated at intervals not to exceed 100 hours time-in-service until the repair is accomplished. If a crack is found in the area of the fourth lightening hole of the vertical fin spar, including a crack in the cap or ``c'' channel area of the spar, or in the left-hand frame sheet, P/N 105-304161 or P/N 1120-30416, or in the right-hand frame sheet, P/N 105-304211 or P/N 1120-30421, before further flight, the crack must be repaired in accordance with the repair instructions that are an Appendix titled ``Repair of BK117 Vertical Fin'' to Eurocopter Alert Service Bulletin MBB-BK117 No. ASB-MBB-BK117-30-106, Revision 3, dated May 5, 1997. Thereafter, this AD requires that a visual inspection for cracks be performed at intervals not to exceed 300 hours TIS. If a crack or loose rivet is found in the area other than that described in paragraph (a) of this AD, including any crack that is found to extend into the skin, P/N 105-304011.18 or P/N 1120-30402.0, contact the Rotorcraft Standards Staff before further flight. Further evaluation is required before further flight. If no crack is found, the repetitive visual inspection for cracks is required at intervals not to exceed 100 hours TIS until the repair specified in the repair instruction is accomplished. The repair must be accomplished within 600 hours TIS after the accomplishment of the initial inspection. Thereafter, the repetitive visual inspections for cracks at intervals not to exceed 300 hours TIS are required. The actions are required to be accomplished in accordance with the service bulletin described previously. Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 97-SW-15-AD.'' The postcard will be date stamped and returned to the commenter. The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39--AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding a new airworthiness directive (AD), Amendment 39-10153, to read as follows: 97-20-16 Eurocopter Deutschland GmbH (ECD): Amendment 39-10153. Docket No. 97-SW-15-AD. Supersedes priority letter AD 97-09-16. Applicability: Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1 helicopters, certificated in any category. Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (f) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no [[Page 52657]] case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD. Compliance: Required as indicated, unless accomplished previously. To prevent failure of the tail boom vertical fin (vertical fin) and subsequent loss of control of the helicopter, accomplish the following: (a) Before further flight, remove the tail rotor drive shaft between the intermediate and tail rotor gearboxes and the yaw servo (if installed). Thoroughly clean the vertical fin spar and adjacent areas and visually inspect the following for cracks or loose rivets: (1) Both surfaces of the vertical fin spar, part number (P/N) 105-304061.03, P/N 1120-30406.03, or P/N 117-30423-03, paying particular attention to the area extending from the top edge of the third lightening hole from the top of the vertical fin spar to halfway between the fourth and fifth lightening hole (see Figure 1). (2) The skin and left-hand and right-hand frame sheets. (b) If a crack or loose rivet is found in the area described in paragraph (a) of this AD (see Figure 1), before further flight, repair in accordance with the Appendix, ``Repair of BK117 Vertical Fin'', to Eurocopter Alert Service Bulletin MBB-BK117 No. ASB-MBB- BK117-30-106, Revision 3, dated May 5, 1997. Thereafter, perform the inspection described in paragraph (a) of this AD at intervals not to exceed 300 hours TIS. (c) If a crack or lose rivet is found in the area other than that described in paragraph (a) of this AD, including any crack that is found to extend into the skin, P/N 105-304011.18 or P/N 1120- 30402.08, before further flight, contact the Rotorcraft Standards Staff. Reporting requirements have been approved by the Office of Management and Budget and assigned OMB control number 2120-0056. (d) If no crack or loose rivet is found as a result of the inspection required by paragraph (a) of this AD, thereafter, until the repair is made in accordance with the Appendix, ``Repair of BK117 Vertical Fin'', to Eurocopter Alert Service Bulletin MBB-BK117 No. ASB-MBB-BK117-30- 106, Revision 3, dated May 5, 1997, conduct the visual inspection required by paragraph (a) of this AD at intervals not to exceed 100 hours TIS. (e) Within 600 hours TIS after the effective date of this AD, accomplish the repair to the vertical fin in accordance with the Appendix, ``Repair of BK117 Vertical Fin'', to Eurocopter Alert Service Bulletin MBB-BK117 No. ASB-MBB-BK117-30-106, Revision 3, dated May 5, 1997. Thereafter, perform the visual inspection required by paragraph (a) of this AD at intervals not to exceed 300 hours TIS. (f) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Standards Staff. BILLING CODE 4910-13-U [[Page 52658]] [GRAPHIC] [TIFF OMITTED] TR09OC97.025 BILLING CODE 4910-13-C [[Page 52659]] Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff. (g) Special flight permits will not be issued. (h) The inspections and repair shall be done in accordance with Eurocopter Deutschland GmbH (ECD) Alert Service Bulletin ASB-MBB- BK117-30-106, Revision 3, dated May 5, 1997, including Appendix. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. Copies may be inspected at the FAA, Office of Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Note 3: The subject of this AD is addressed in Luftfahrt- Bundesamt (Germany) AD 97-144/2, dated June 5, 1997. (i) This amendment becomes effective on October 24, 1997. Issued in Fort Worth, Texas, on September 26, 1997. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 97-26792 Filed 10-8-97; 8:45 am] BILLING CODE 4910-13-U